Polyene hydrocarbons and process for obtaining same

ABSTRACT

Triene hydrocarbons containing two conjugated double bonds, represented by the formula: WHEREIN R1, R2, R3, R4, R and R&#39;&#39; may be hydrogen, alkyl or aryl radicals, and which may be prepared through a Diels-Alder reaction between a cyclopentadiene and (a) a dihalide-alkenyl compound, followed by dehydrohalogenation with basic agents, or (b) esters of fumaric or maleic acid, followed by reaction with a Grignard&#39;&#39;s reagent and then by dehydration of the alcohol, are disclosed.

0 United States Patent 1151 3,676,5 1 0 Arrighetti et a1. 45 July 11,1972 1 1 POLYENE HYDROCARBONS AND 3,220,988 11/1965 Hoch 260/666 PYPROCESS FOR OBTAINING SAME 3,347,944 10/1967 Fritz ....260/666 PY3,214,483 10/1965 Cripps ..260/666 FY [72] Inventors: Sergio Arrighetti,M11an; Eugenio Vajna; e i m Cesca, h of San Donate PrimaryExaminer-Delbert E. Gantz M1lanese, all of Italy AssistantExaminer-Veronica OKeefe [73] Assignee: Snam Progetti S.p.A., Milan,Italy Anomey Ralph Watson [22] Filed: Jan. 22, 1971 [57] ABSTRACT [21]Appl. No.: 109,007 Triene hydrocarbons containing two conjugated doublebonds, represented by the formula: [30] Foreign Application PriorityData 1'1 f Jan. 22, 1970 Italy ..I9658 R2 [52] US. Cl ..260/666 PY,260/666 A 51 1m. (:1 [58] Field of Search 260/666 A, 666 PY wherein R RR R R and R may be hydrogen, alkyl or aryl radicals, and which may beprepared through a Diels- 5 References Ci d Alder reaction between acyclopentadiene and (a) a dihalidealkenyl compound, followed bydehydrohalogenation with basic agents, or (b) esters of fumaric ormaleic acid, followed UNITED STATES PATENTS by reaction with a Grignardsreagent and then by dehydration of the alcohol, are disclosed.

3 Claims, No Drawings POLYENE HYDROCARBONS AND PROCESS FOR OBTAININGSAME The present invention relates to new polyene hydrocarbons and tothe process for obtaining same.

More particularly the present invention relates to triene hydrocarbonscontaining two conjugated double bonds and having the following generalformula:

cyclopentadiene and dihalide-alkenyl compounds, and then of adehydroalogenation by basic agents:

In the above reaction schemes R, R R R R R and R" have the aforesaidmeanings, and X is a halogen as Cl, Br or I. The reactions according tothe process of the present invention are carried out at a temperaturecomprised in the range from -l0 to 100 C and in the presence of asolvent which may be selected from esters as tetrahydrofurane, dioxane,ethyl ether, butyl ether and the like, or aromatic hydrocarbons asbenzene, toluene, xylenes or mixtures of the cited solvents.

Typical unrestrictive examples of triene compounds according to thepresent invention are the following ones:

H CH (lllzi lll C H-C H3 2,3-dietliyllden-norbonS-ene The invention isnow illustrated by the following unrestrictive examples.

EXAMPLE I In a vessel provided with a reflux condenser, a loading funneland a stirrer, 2 moles of cyclopentadiene were added to 2 moles of atoluene suspension of dimethylfumarate, the adding being carried outdrop by drop. The reaction was finished after 24 h, and the obtainedproduct was distilled (0.2 mmHg) at 96+98 C after the toluene solutionhad been washed by a saturated solution of NaHCO,

The product, dissolved into ethyl ether, was dropped into a solution ofCH Mgl (8 moles). The adding having been finished, the obtained mixturewas allowed to reflow under stirring for 24 hours, then the magnesiumsalt were hydrolized by a watery solution of CH COOH.

It was extracted by ether, the extract was washed by a solution of NaHCOand the solvent was removed by distillation.

The resulting alcohol was purified by crystallizing it from pentane; itwas dehydrated by dissolving into pyridine, and dropping 4 moles of SOCl into the reaction solution, at 0 C. After about 60 minutes, thesolution was returned to room temperature, then treated by a waterysolution of CH COOH, extracted by ether, and the extract was washed by asolution of NaHCO A product was isolated by an isomerization employingtri dialkylamides of the phosphoric acid as catalysts (French Patv1.529.455) and then by a distillation, which product had MW 174 and b.p.+80 C/l mmHg.

The gas-chromatographic retention time (on 3 m EAS column on 5 percentof 60-80 mesh firebrick) was 4 minutes 2 seconds at l50 1 C.

The total yields were 25 percent. The spectroscopic investigationsshowed agreement with the compound 1.

EXAMPLE ll An ether solution of 2,3-diacetyl norbor-5-ene was slowlydropped into an ether suspension of AIH,

The obtained alcohol was dehydrated by S0 Cl and pyridine at 0 C byworking according to example 1.

According to the above working procedure, a mixture of products wasisolated, which were isomerized by means of catalysts of the typetridialkylamides of phosphoric acid (F.P. 1.529.455); a product wasseparated by distillation; which product had M.W. 146 and showed a goodagreement to the compound lV.

What we claim is:

l, Polyene hydrocarbons containing two conjugated double bonds havingthe following general formula:

in which R R R R R and R are hydrogen. alkyl or aryl radicals.

2. A process for preparing polyene hydrocar in claim 1 consisting inreacting a diene as with a. dihalide alkenyl as lions as claimed UNWEUSTATES PATENT @FFEQE *CERTIWCATE @F IMEREQTWN Patent No. 3,676,510 DatedJuly 11 1972 Inventor) Sergio Arrighetti, et a].

it is eewtified'thm: emrmr eppemw m ti'aeaflwve idiemtfiied patent andthat sew Lettewre 'Eatem: we hereby eeweemi as shew Faelew:

Column 3, correct the first formula to reafi:

Signed and sealed this 19th day of February 1974.

(SEAL) Attes't:

EDWARD M.FLETCHER-,JR. Attesting Officer C. MARSHALL DANN Commissionerof Patents

2. A process for preparing polyene hydrocarbons as claimed in claim 1consisting in reacting a diene as
 3. A process for preparing polyenehydrocarbons as claimed in claim 1 in which said hydrocarbons areobtained by a Diels-Alder reaction between cyclopentadiene and an esterof the fumaric or maleic acid, by a following reaction with a Grignardreactant and then by dehydrating the so obtained alcohol.